Disk strain-insulator.



APPLICATION HLED JAN- 3 I913.

Patented Apr. 24,1917.

R 0 TI m y N I ATTORNEY WITNESSES lowing is a specification.

LOUIS STEINBERGER', 0F BRGOKLYN, NEW YORK.

msx srnam-rnsunaron. i

Specification of Letters. Patent.

Patented Apr. 24, 1917.

Application filed January 3, 1913. serial No. 739,988.

To all whom may concern:

Be it known that I, LOUIS Srnmenncnu, residing at Brooklyn, in thecounty of Kings and State of N ew York, have invented certain new anduseful Improvements in Disk Strain-Insulators, of which the fol- Thlsinvention relates to strain insulators,

and particularly to those of the disk type.

A particular object of the invention is to provide an insulator of thisclass wherein the irregularities of surface, for providingwater shedsand otherwise increasing the insulating value of the disk withoutincreas ing the size of the disk, are arranged in such manner that theyare amply supported from the body without depending for their supportupon the strength of intervening relatively weak portions of thestructure.

A further object is to'provide a structure as above, which comprisesridges formed on the surface of the disk radiating from the body, and toshape, or curve, the ridges after leaving the body, so as to dispose aplurality of distinct ridges in the path of any current tending to creepradially across the surface of the disk.

A further object is to provide a disk with ridges on its oppositesurfaces radiating from the body of the insulator, and to shape, orcurve", the ridges upon the opposite surfaces of the disk' in suchdirections that portions of the ridges upon the respective surfaces willlie in intersecting planes for lending added strength to the structure.

A further object is to provide a structure, as above, which is simple ofdesign, which comprises a minimum of material and which is thereforecheap to manufacture, but is nevertheless thoroughly substantial andembodies maximum efliciency, both as to its insulating qualities and asto its mechanicalstrength, for a given sized disk.

A further object is to provide an insulator comprising spacedconductors, to provide means intermediate the conductors definingcreepage paths, and to so shape the paths as to obtain maximumefiic1ency for a given size insulator.

Other objects and aims of the invention, more or less specific thanthose referred to above, will be in part obvious and in part pointed outin the course description of the elements, combinations, arrangements ofparts and applications of principles, constituting the invention; andthe scope of protection contemplated will be indicated in the appendedclaims.

In the accompanying drawings which are.

to be taken as a and in which I ferred form of tion:

Figure 1 is a top plan View of an insulator constructed in accordancewith the principles of this invention;

Fig. 2 is a side elevational view of the structure shown in Fig. 1;parts being shown in section and the plane of line 22 of said figure;

Fig. 3 is a fragmentary, detail, sectional view, taken substantiallyonthe plane of line 83 of Fig. 1.

Referring to the drawings for a more de tailed description of thestructure illustrated, the numeral 1 indicates the body portion of theinsulator, which portion is preferably of a more or less elongatedcylindrical shape, adapted for receiving the strain members illustratedat 2 and 3.

The strain members illustrated each comprise a short bolt having an eye,as 4, at its outer end, and having its inner end formed with a head 5,shown in dotted lines in Fig.

part of this specification, have shown a merely preembodiment of theinven- 2. The inner ends of the two strain memhere are spaced apart andthe material of the body fills the intervening space for ef-' andcomprises a wall or annular flange of of the following I tend in acurved substantially uniform thickness springing from the body 1 betweenthe ends of the body, preferably at the transverse median line of thebody.

Formed upon the upper surface of the wall or flange forming thediskportion 6 is a plurality of ridges 7, each of the ridges extending fromthe body portion 1 preferably to or near the outer peripheral edge ofthe disk. These ridges preferably leave the body substantially radiallythereof and exconvolute or spiral direction along the surface of thedisk toward the periphery thereof.

The ridges may be considered as mergin together in a common point at thebody, an there is preferably enough of them, and their shape is such,that the outer portions of any one of them radially overlap atleast oneor more of the adjacent ridges, so that a line drawn radially from thecenter of the disk will intersect at least two ridges. ThlS arrangementis not a positive requirement for effective operation of the structure,but is a preferable one. As many or as few ridges may be employed asdeemed desirable for meeting various requirements, both as towithstanding different degrees of potential and of attaining requiredmechanical strength.

The thickness of the material forming the wall or flange 6 maypreferably be only sufficient to=lend efliciency against puncturing andfor lending the required mechanical strength to reinforce the outerportions of the ridges.

The ridges 7 are preferably of a relatively greater cross sectional areawhere they merge together, or into the body of the insulator, andgradually decrease in proportions toward the periphery of the disk, asclearly 'hown in the drawing. This will lend strength to the structure,both electrically and mechanically.

In order to further strengthen the structure, and to more effectuallyguard against puncture, it may be desirable to increase the thickness ofthe wall or flange 6 in the vicinity of the body 1. The flange may bemade thickest adjacent the body and be of gradually decreasing thicknesstoward the edge, or it may be otherwise reinforced, as desired. Here itmay be notedthat whereever in this specification or claims, the termsubstantially of uniform thickness or its equivalent is employed todescribe the portion 6, such term is intended to include any variationsin thickness which may be desirable for lending required strength andresistance to puncturing to the part.

It is apparent that the structure shown and described, provides sionsradially of the disk, with all the advantages thereof, but without thenecessity for proportioning the intervening parts of shown two lines,

ridges and depresthe disk between the ridges beyond the requirements forpreventing puncture. The integral connection of the ridges with the bodygreatly increases the mechanical strength of the structure.

It should be noted that though I have shown and described the ridges 7as being distinctly prominent and spaced apart by substantially flatportions of the flange or wall 6, it is however obvious that theseridges could as well be rounded on their surfaces, one ridge merginggradually into the next adjacent ridge, or they may be given any otherdesired cross sectional contour, within the spirit of this invention.

It is apparent that the depressions or grooves formed between the ridges7 serve to present relatively dry areas even in the presence of rainfall. At least one side of the structure will necessarily be almostentirely dry. These depressions or grooves also define creepage pathsradiating from the center of the disk and, by reason of the convolute orspiral direction of the ridges, the creepage paths are considerablylonger than the radial dimension of the disk. The proportions of theridges may be calculated so as to cause the space between them to serveas creepage paths throughout the length of the ridges.

.Supposing the insulator to be arranged with its axis substantiallyhorizontal, as

illustrated in Fig. 1, water, as rain, striking the surface will beconducted around the body 1, and will fall off the lowest point of theinsulator. In the drawings there are X and Y, for indicating theprobable path of a great proportion of such water as would strike thetop of the insulator at the points of the lines X and Y. It will benoticed that these lines follow paths of easiest flow indicated by theshape of the ridges, and that water following these paths will beconducted away from the body 1, and consequently away from the strainmembers within the body. Such water as may strike the top of theinsulator intermediate the lines X and Y, will robably follow anintermediate path as in icated by the line Z, which path may conduct thewater nearer to the'body than either of the paths X and Y. The amount ofwater following the path Z, however, practically negligible, and willreach the body at one side of the center thereof, and will be conductedaround that side of the body and prevented from moving toward the strainmember at the end of the body. Due to the influence of surface cohesion,some of the water may follow directly along the ridges and into thepockets 8 formed adjacent the body between the ridges, rather thanfollow the steeper and easier paths indicated by the lines X and Yfbutsince the body pro ects beyond the outer edge of the is so small as tobe I rain water.

ridges, this water will pass around the sides of the body toward thebottom rather than to the end of the body.

The opposite surface of the wall or flange 6 is provided with ridges inevery way similar to those already described, and these ridges may bearranged directly beneath the ridges described, if desired. They arehowever preferably curved in a relatively opposite direction, as shownbest by dotted lines 9 in Fig. 1, so that the ridges upon the twosurfaces of the disk cross or intersect each other to lend ture. Thecreepage paths are also lengthened by this arrangement. In thearrangement shown each of these paths follows a line extending from oneside of one conductor, making a wide circle across one surface of thedisk to the periphery thereof, and continues across the other surface ofthe disk to a relatively opposite side of the other conductor. Maximumefliciency against creepage is thus secured for a given sized disk.

en desired, an annular groove 10 may be formed upon the periphery ofthedisk by the addition of obliquely projecting flanges 11 which will serveto efiectually protect the surfaces of the disk from direct attack ofSuch water as strikes the flanges 11 will be conducted to the lowestpoint and fall off surface of the disk.

As many changes could be made in this construction without departingfrom the scope of the following claims, it is intended that all mattercontained in the above description or shown in the accompanying drawingshall be interpreted as illustrative only and not in a limiting sense.

Having thus described my invention what I claim as new and desire tosecure by Let ters Patent, is:

1. In an insulator, a disk formed with a plurality of ridges thereonradiating from a common point and extending in curved directlons so thatone ridge overlaps a portion of another ridge radially from said commonpoint.

2. In an insulator, a disk formed with a central body portion, and aseries of ridges formed on said disk extending from said body portionin; curved directions toward the margin of the disk, and a portion ofone of said ridges overlapping a portion of another of said ridgesradially from said body portion.

3. In an insulator, a disk, and means'thereon defining a plurality ofcreepage paths extending in curved directions from the central portionof the disk toward theperiphery thereof, said paths having portlonsoverlapping radially from said central portion of. the disk.

4. In an insulator, a disk having relatively upper and lower surfaces, aplurality of added strength to the struc-- without reaching eithercentral part of spaced and separate ridges extending along said twosurfaces in a spiral direction, and the ridges on one surface extendingin a spiral direction opposite to the direction of the ridges on theother surface.

In an insulator, a disk having a plurality of ridges upon each of itsopposite surfaces defining creepage paths between them, there being acreepage path upon one surface to form a pair with each creepage pathupon the opposite surface, the tWo creepage paths of each of said pairsextending from the central portion of the disk in substantiallydiametrically opposite .directions but being curved so as to terminateadjacent a common point in the vicinity of the periphery of the disk.

In an insulator, a disk having a plurality of curved ridges on each ofits opposite surfaces, the ridges on each surface radiating from acommon point, and the ridges on one surface curving in a directionopposite to the direction of curve of the ridges on the other surface,and portions of the ridges on one surface overlying portions of theridges on the other surface.

'3'. A disk insulator having a creepage path upon each of its oppositesurfaces, the creepage path upon one surface forming a pair with thecreepage path upon the opposite surface, the two creepage pathsextending from the central portion of the disk in substantiallydiametrical opposite directions, but being curved so as to terminateadjacent a common point in the vicinity of the periphery of the disk.

8. In an insulator, a disk having a plurality of ridges on each of itsopposite surfaces, the ridges on each surface radiating from a commoncentral point and extending in curved directions toward the margin ofthe disk, the ridges upon the respectivesurfaces of the disk beingdisposed so that relatively outer portions of each overlap relativelyinner portions of adjacent ribs radially of the disk. p

9. In an insulator, a disk having a plurality of ridges on each of itsopposite surfaces, the ridges on each surface radiating from a commoncentral point and extending in curved directions to the margin of thedisk, the ridges upon the respective surfaces of the disk being disposedso that relatively outer portions of each overlap relatively innerportions of adjacent ribs radially of the disk, said ridges upon therespective surfaces of the disks defining creepage paths between themextending outwardly from the the disk to the margin of the disk, alsosaid ridges being disposed so that each creepage path upon one surfaceforms a pair with a creepage path upon the opposite surface, each pairconstituting a continuous creepage path extending from the centralportion of the disk outwardly in a curved direction along one surface ofthe In testimony whereof, I aflix my signadisk and inwardly along theopposite surture in the presence of two witnesses. face to the centralportion of the disk, ap- LOUIS STEINBERGER proaching the central portionin a direction 5 substantially diametrically opposite to the Witnesses.

direction in which it left said central por- L. GERSFORD HANcrm, tion.NATHALIE THOMPSON.

